Fibonacci sequence via Enumerator

fibonacci.rb

def fibonacci(numbers_count)
  sequence = Enumerator.new do |yielder|
    current_number, next_number = 0, 1
    
    loop do
      yielder << current_number
      current_number, next_number = next_number, current_number + next_number
    end
  end
  
  numbers_count.times.map { sequence.next }
end

p fibonacci(20)
# => [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181]